def falling(n, k):
    """Compute the falling factorial of n to depth k.

    >>> falling(6, 3)  # 6 * 5 * 4
    120
    >>> falling(4, 3)  # 4 * 3 * 2
    24
    >>> falling(4, 1)  # 4
    4
    >>> falling(4, 0)
    1
    """
    "*** YOUR CODE HERE ***"
    if k == 0:
        return 1

    sum = 1

    counter = 0

    while counter < k:
        sum = sum * (n - counter)
        counter += 1

    return sum


def sum_digits(y):
    """Sum all the digits of y.

    >>> sum_digits(10) # 1 + 0 = 1
    1
    >>> sum_digits(4224) # 4 + 2 + 2 + 4 = 12
    12
    >>> sum_digits(1234567890)
    45
    >>> a = sum_digits(123) # make sure that you are using return rather than print
    >>> a
    6
    """
    "*** YOUR CODE HERE ***"
    sum=0
    while y>0:
        sum+=(y%10)
        y=y//10
    return sum

def double_eights(n):
    """Return true if n has two eights in a row.
    >>> double_eights(8)
    False
    >>> double_eights(88)
    True
    >>> double_eights(2882)
    True
    >>> double_eights(880088)
    True
    >>> double_eights(12345)
    False
    >>> double_eights(80808080)
    False
    """
    "*** YOUR CODE HERE ***"
    sum=0
    flag=0
    flag1=0
    flag2=0
    while n>0:
        flag1=n%10
        n=n//10
        flag2=n%10
        if(flag1==8 and flag2==8):
            flag=1
    if flag==1:
        return True
    else:
        return False

